Addition of LTV for SBA tests

Follow-up from sa4/audio/ivas-basop#782 (closed)

It would be desirable to be able to run the following SBA tests using the long test vectors (LTV):

• tests/codec_be_on_mr_nonselection/test_sba_bs_dec_plc.py
• tests/codec_be_on_mr_nonselection/test_sba_bs_enc.py

A starting point exists here: https://forge.3gpp.org/rep/ivas-codec-pc/ivas-codec/-/tree/add_ltv_to_sba_pytests